Overhead conveyor systems are widely used in manufacturing and material handling operations; and are particularly ubiquitous in the animal butchering industries, such as processing plants for poultry and other fowl. The conveyors are used to move the carcasses through the plant in assembly-line like fashion. The conveyor system typically includes an elevated suspended guide rail, which is a beam having an I, H, T or channel iron shape, and a series of interconnected wheeled trolley elements which hang from the rail and are coupled to each other through a flexible chain like linkage. In the I beam rail configuration, which is the most popular, the trolleys have a pair of bearing wheels which ride on the upper surface of the lower flange of the I beam. The wheels extend from a yoke frame that girdles beneath and is centered on the web of the I beam. The wheels are spaced from each other by a width that is just slightly greater than the thickness of the web of the I beam, such that one wheel cannot slip off the lower flange, as the opposed wheel will encounter the web of the I beam. The chain like linkage is propelled, usually by a powered sprocket, and this in turn moves the trolleys along the guide rail.
In poultry processing plants the conveyor system is used to carry the bird to and from the numerous work stations as the bird is incrementally processed into a food product. Because the conveyed material is a food product, an essential performance criteria is that the conveyor is kept clean of oil, dirt and other types of grime and contamination. Throughout the processing steps, which include killing, scalding, depluming, cropping the head and feet, and evisceration, there are a lot of small bits of flesh, oil, bone, et cetera generated, and so, the carcass, which is suspended from a shackle attached to the yoke frame of the trolley, becomes littered with this debris. To correct this the bird is rinsed over and over to remove remnants of the the last work station and insure cleanliness. One of the sources of contamination can also be the overhead conveyor itself, because it, and in particular the trolleys are exposed to many of the processing operations, and so the conveyor is cleaned during the cleanup shift. A problem with cleaning the conveyor only on the cleanup shift is that the level of contamination tends to increase from this source as the production shift lengthens; and so in-line continuous cleaning would be preferable.
Bowman'4,678,075 discloses an overhead conveyor cleaning device for cleaning conveyors used in electrostatic painting operations that employees an assemblage of brushes that scrap the trolley and chain-like linkage as they proceed past the device, therein enabling continuous operation of the conveyor. In butchering operations, and particularly in poultry processing, copious quantities of water are needed to achieve the required level of cleanliness, and brushes in and of themselves would be inadequate to the task. Also, because water is used in processing the bird, debris, and especially remnants, are deposited and impacted in the smallest seams and orifices of the overhead conveyor.
An interior side of a trolley wheel adjacent to the web of the guide rail is one of the more particularly difficult parts of the conveyor system to clean, and can be a major source of contamination. The contamination problem is further aggravated because of the accompanying mechanical action of the wheel which serves to distribute the contamination throughout the entire length of the conveyor system, and to speed up the breakdown of remnants by the abrasive action of a wheel riding along the guide rail. Water sprays emanating from sources designed to clean the carcass are not very effective because the body of the trolley wheel is interposed between the interior side of the trolley wheel and the directed spray of water. The upper flange of the guide rail shrouds the interior side of a trolley wheel from an overhead washing stream of water.
The present invention is an apparatus that cleans the trolley wheels, and in particular the interior sides of the trolley wheels, to a degree and in a manner that is suitable to standards established and enforced by the United States Department of Agriculture.